Coordinated Transmission and Control for Audio Output Devices

ABSTRACT

Methods performed by a first sink device, a source device, or a second sink device. The first sink device is connected to a source device via a first communication link and a second sink device via a second communication link, wherein the second sink device is configured to eavesdrop on communications between the first sink device and the source device on the first communication link. The methods include determining an occurrence of a trigger event and modifying an operation of at least one of the first sink device, the second sink device or the source device based at least on the trigger event occurring.

PRIORITY INFORMATION/INCORPORATION BY REFERENCE

This application claims priority to U.S. Provisional Application62/737,252 entitled “Coordinated Transmission and Control for AudioOutput Devices,” filed on Sep. 27, 2018, the entirety of which isincorporated herein by reference.

BACKGROUND INFORMATION

A short-range wireless communication protocol enables communications tobe exchanged wirelessly between two or more devices. For example, thefirst device may be a source device providing audio data to the seconddevice. The second device may be a sink device that receives the audiodata and generates an audio output. The second device may be a single,integrated device such as headphones or an earpiece. Headphones mayinclude two audio components that have a wired connection. An earpiecemay include one audio output component. However, in each case, for theshort-range transmission, the second device utilize a singlecommunication link between the source device and the sink device.

The second device may also be a paired device including a first sinkdevice and a second sink device. In such an implementation, the seconddevice may utilize a first communication link between the source deviceand the first sink device (e.g., which acts as a primary sink device).The first communication link may be established directly such that boththe source device and the first sink device acknowledge one another inthis link. The second device, which acts as a secondary sink device,eavesdrops on the first communication link to receive any communicationsbeing transmitted over the first communication link. Thus, the sourcedevice and the second device have an indirect relationship such that thesecond sink device recognizes transmissions over the first communicationlink, but the source device may be unaware of the second sink device.

When the second device is a paired device or multiple devices includinga first sink device and at least one second sink device, scenarios mayarise when either the first sink device or the second sink device do notreceive the communication. Thus, only one device is capable ofoutputting the corresponding audio while the other sink device remainssilent. This results in a poor user experience when at least one of thesink devices is unable to produce the proper output.

SUMMARY

In an exemplary embodiment, a method is performed by a first sink deviceconnected to a source device via a first communication link and a secondsink device via a second communication link, wherein the second sinkdevice is configured to eavesdrop on communications between the firstsink device and the source device on the first communication link. Themethod includes determining an occurrence of a trigger event andmodifying an operation of the first sink device based at least on thetrigger event occurring.

In a further exemplary embodiment, a method is performed by a sourcedevice configured to transmit a packet via a first communication link toa primary sink device, wherein a secondary sink device is configured toreceive the packet by eavesdropping on the first communication link. Themethod includes receiving first link statistics associated with thefirst communication link between the primary sink device and the sourcedevice and second link statistics associated with an eavesdropcommunication link between the secondary sink device and the sourcedevice and determining a setting to be used in transmitting a furtherpacket via the first communication link to the primary sink device.

In a still further exemplary embodiment, a source device having atransceiver and a processor is described. The transceiver is configuredto establish a first communication link with a primary sink device andtransmit a packet, in accordance with one or more settings, to theprimary sink device via the first communication link, wherein asecondary sink device is configured to receive the packet byeavesdropping on the first communication link. The processor isconfigured to determine first link statistics associated with the firstcommunication link between the primary sink device and the source deviceand second link statistics associated with an eavesdrop communicationlink between the secondary sink device and the source device. Theprocessor is further configured to determine the settings to be used intransmitting the packet to the primary sink device via the firstcommunication link.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an exemplary system of components utilizing short-rangecommunication links according to various exemplary embodiments describedherein.

FIG. 2 shows select components of the exemplary system of FIG. 1according to various exemplary embodiments described herein.

FIG. 3 shows a first exemplary scenario and corresponding mechanism forsink devices to receive a short-range transmission according to variousexemplary embodiments described herein.

FIG. 4 shows a second exemplary scenario and corresponding mechanism forsink devices to receive a short-range transmission according to variousexemplary embodiments described herein.

FIG. 5 shows a third exemplary scenario and corresponding mechanism forsink devices to receive a short-range transmission according to variousexemplary embodiments described herein.

FIG. 6 shows a fourth exemplary scenario and corresponding mechanism forsink devices to receive a short-range transmission according to variousexemplary embodiments described herein.

FIG. 7 shows a fifth exemplary scenario and corresponding mechanism forsink devices to receive a short-range transmission according to variousexemplary embodiments described herein.

FIG. 8 shows a sixth exemplary scenario and corresponding mechanism forsink devices to receive a short-range transmission according to variousexemplary embodiments described herein.

FIG. 9 shows a seventh exemplary scenario and corresponding mechanismfor sink devices to receive a short-range transmission according tovarious exemplary embodiments described herein.

DETAILED DESCRIPTION

The exemplary embodiments may be further understood with reference tothe following description and the appended drawings, wherein likeelements are referred to with the same reference numerals. The exemplaryembodiments describe devices, systems, and methods to coordinateshort-range transmissions from a first device to a wirelessly pairedsecond device using a wireless communication link. The exemplaryembodiments include a plurality of mechanisms that improve the manner inwhich the short-range transmissions are transmitted by a source deviceand received by a plurality of sink devices to increase the probabilitythat all of the sink devices receive the short-range transmissions. Afirst mechanism may involve operations performed by the sink devicesthat are transparent to the source device. A second mechanism mayinvolve operations performed by the sink devices to provide informationto the source device to modify transmission settings. A third mechanismmay involve operations performed by the source device to ascertaininformation that modifies transmission settings.

Initially, the exemplary embodiments are described with regard to aBluetooth connection. However, the use of the Bluetooth connection andcorresponding operations associated with the Bluetooth connection isonly exemplary. The exemplary embodiments may be modified to be usedwith any type of wireless connection, particularly a peer-to-peerconnection, and corresponding operations associated with the wirelessconnection. For example, the exemplary embodiments may also be used whenthe connection is a WiFi Direct connection.

The exemplary embodiments are also described with regard to anelectronic device such as a user equipment performing operationscorresponding to a source device and/or a sink device. However, theelectronic devices as described herein are only exemplary. The exemplaryembodiments may be utilized with any device that may establish ashort-range connection (e.g., Bluetooth connection). The arrangementincluding a source device and sink device is also only exemplary. Theexemplary embodiments may relate to any two devices that establish theBluetooth connection in which data is exchanged. In addition, the use ofthe terms source and sink to signify a master and subordinaterelationship is only exemplary. For example, the connected devices mayeach operate as a source and a sink over the same connection atdifferent times, examples of which are provided below.

The exemplary embodiments are further described with regard to thesource device being a device such as a smartphone or a tablet computerand the sink devices being audio buds where the source device transmitsaudio packets to the sink device. However, the exemplary source and sinkdevices should only be considered examples and some other examples ofsource and sink devices will be provided below. Also, the use of audiopackets is only exemplary. The exemplary embodiments may be implementedfor any type of electronic devices that transmit and/or receive any typeof data. For example, when the sink devices are video output devicesthat display the same video, the data may be video data and/ormultimedia data.

As described above, a direct communication link may be establishedbetween the source device (e.g., smartphone) and a primary sink device(e.g., first wireless audio earbud) and an indirect communication linkmay exist for the source device and a secondary sink device (e.g.,second wireless audio earbud). However, further communications links mayalso be established between the multiple sink devices. For example, theprimary sink device and the secondary sink device may form acommunication link to exchange data. In this communication link, it maybe considered that the primary sink device is also a source device andthe secondary sink device is the sink device for this furtherconnection. In another example, one of the wireless audio earbuds mayalso include a microphone that receives audio input from a user (e.g.,when the user is on a voice call). In this scenario, the wireless audioearbud may be transmitting audio packets to the smartphone. Thus, inthis example, the wireless audio earbud may be considered the sourcedevice and the smartphone may be considered the sink device. In a stillfurther example, one of the devices may be a hearing aid that transmitsthe audio that it receives to the smartphone (e.g., for furtherprocessing of the audio signal, transcription, recording, etc.). Again,in this example, the hearing aid may be considered the source devicetransmitting the audio signal to the smartphone that is the sink device.As these examples illustrate, devices may act as both a source and asink (sometimes simultaneously) depending on the various communicationlinks that have been established by the device.

The exemplary embodiments relate to configurations where a source devicetransmits short-range communications or packets to a plurality of sinkdevices over a Bluetooth connection. For all of the sink devices toreceive the packet, a valid and usable communication pathway from thesource device to each of the sink devices must exist. Although there arevarious settings and configurations that are utilized to improve themanner of the sink devices receiving the packet, there may also be otherconsiderations that prevent consistent use of these settings andconfigurations. For example, a higher transmit power may provide agreater transmission range to allow sink devices positioned at a greaterdistance from the source device to receive the packet. However, use ofthe higher transmit power consumes a greater amount of battery power.There is a tradeoff in using select settings to control transmissionoperations.

There are also a variety of scenarios and underlying reasons that mayprevent one or more of the sink devices from receiving the packet. In afirst example, there may be a significant delta in received signalstrength indicator (RSSI) values when the sink devices are positioned ina cross-body position (e.g., a first sink device in one ear, a secondsink device in another ear). For example, the RSSI delta may beapproximately 15 dB. The RSSI delta may not be accurately accounted forin settings used by the source device (e.g., transmit power),particularly when the source device uses information associated with thesink device having the best reception.

In a second example, an instantaneous RSSI delta between sink devicesmay be significant (e.g., relative to an average RSSI delta). Forexample, an instantaneous RSSI delta may be up to 40 dB. The increase inthe RSSI delta may be due to various reasons such as fading. When thesource device uses information that corresponds to the instantaneousRSSI delta (as opposed to an average or lesser RSSI delta), the sourcedevice may utilize settings that do not properly account for a true RSSIdelta.

In a third example, among the sink devices, a first sink device mayinclude a user input component. The input may be a gesture control thatis directly entered on the user input component or registered using asensor (e.g., finger-squeeze, hand covering, waving, etc.). The user'sactions may have a significant impact on antenna performance on the sinkdevice. For example, in view of the small form factor associated withcertain sink devices, the impact may cause a degraded wireless link thatresults in audio glitches, unresponsive user interface control issues,etc. In a particular example, the sink device may experience a firstaverage RSSI value. However, during a gesture period, the sink devicemay experience a second, lower average RSSI value. After the gestureperiod, the sink device may again experience the first average RSSIvalue. Therefore, during the gesture period, there may be an increase inlikelihood that an audio error occurs and a rate at which audio errorsoccur may also increase.

In a fourth example, among the sink devices, a first sink device may bea primary sink device while all remaining sink devices may be consideredsecondary sink devices. As described above, a direct communication linkmay only be established between the source device and the primary sinkdevice while secondary sink devices eavesdrop this communication link.In this scenario, the source device may only be aware of the presence ofthe primary sink device. If the source device has a strong communicationlink with the primary sink device (e.g., based on a RSSI value), thesource device may not utilize a high or maximum transmit power. At thesame time, one or more secondary sink devices may have a weak link toeavesdrop the communication link. There may be various reasons for thesecondary sink device to exhibit the weaker link (e.g., cross-bodyattenuation, gesture control covering the secondary sink device, etc.).Therefore, the primary sink device having a strong communication linkmay result in use of a lower transmit power, but this may result in thesecondary sink device having continuous poor packet reception leading toaudio glitches. In this example, the RSSI delta is not accuratelyaccounted for in the transmit power control of the source device.

In a fifth example, there may be an opposite configuration from thefourth example where the source device has a weak communication linkwith the primary sink device while the secondary source device may havea strong link to eavesdrop the communication link. In such a scenario,the source device may constantly use a high transmit power to cover therelatively poor communication link with the primary source device at thecost of reduced battery life of the source device.

In a sixth example, the source device may be configured with antennadiversity, transmit diversity, beam forming, coexistence schemes,specific absorption rate (SAR) schemes, etc. to transmit packets to theprimary sink device. The diversity scheme may continuously select anantenna, transmit settings or a beam former that works well with theprimary sink device. However, with the source device being unaware ofthe existence of the secondary sink devices, the diversity scheme maynot work well with the secondary sink devices. For example, in a crossbody scenario, a first source device antenna may be selected and workwell with the primary sink device that is on the same side of the bodyas the source device, but that first antenna may not provide a goodsignal for the secondary sink device that is on the other side of thebody. Similarly, the source device may select a first beam former thatworks well with the primary sink device, but not the secondary sinkdevice. These examples also show that these types of transmissionsettings may allow the primary sink device to properly receive thetransmissions and output the audio, while audio glitches may occur onthe secondary sink devices.

The above examples describe general problems that may occur whentransmitting packets from a source device to a plurality of sinkdevices. The source device may be considered the master for the overalltransmit quality control. For example, the source device selects thetransmission settings for transmitting packets to the primary sinkdevice. These settings may also control the manner by which thesecondary sink devices receive packets. For example, transmissionsettings may include transmit power, retransmission policies, adaptivefrequency hopping schemes, audio packet scheduling, antenna switchcontrols, beam forming, etc. However, as described above, there arescenarios that result in sub-optimal conditions for the source deviceand/or the sink devices including audio glitches and increased powerconsumption.

The exemplary embodiments provide a plurality of mechanisms that may beimplemented to transmit a packet from the source device to the sinkdevices. In utilizing the mechanisms according to the exemplaryembodiments, the source device may select appropriate settings tobalance transmission quality and other factors such as powerconsumption. The sink devices may also provide features to increase theprobability that all sink devices properly receive the packet.

FIG. 1 shows a system 100 of components utilizing short-rangecommunication links according to the exemplary embodiments. The system100 illustrates a possible network of short-range connections between amaster or source device 105 and an accessory device illustrated as apaired audio device 108 including a primary audio bud or sink device 110and a secondary audio bud or sink device 115. The system 100 shows whenthe short-range connections have been established between the sourcedevice 105 and accessory devices (e.g., the paired audio device 108).For illustrative purposes, the master device or source device may beused interchangeably to represent the device 105; the primary audio budor the primary sink device may be used interchangeably to represent thedevice 110; and the secondary audio bud or the secondary sink device maybe used interchangeably to represent the device 115. The use of a pairedaccessory device is only exemplary, and the exemplary embodiments may beimplemented or modified to be used with multiple sink devices includingmore than two sink devices.

A source-to-audio bud (S2B) link 120 is a short-range communication linkthat may be established between the source device 105 and the primaryaudio bud 110. An audio bud-to-audio bud (B2B) link 125 is a short-rangecommunication link that may be established may be between the primaryaudio bud 110 and the secondary audio bud 115. The secondary audio bud115 may also be configured to perform an eavesdrop 130 (or snoop) ondata being exchanged on the S2B link 120 or being broadcast/transmittedby the source device 105. The system 100 may also include furthershort-range communication links such as between the source device 105and the secondary audio bud 115 (not shown). In one example, theshort-range communication links may be Bluetooth connections.

The exemplary embodiments refer to the eavesdrop 130 as a communicationpathway, a connection, a link, etc. However, the eavesdrop 130 is anoperation performed by the secondary audio bud 115 to monitor the S2Blink 120 and transmissions exchanged over the S2B link 120. Thismonitoring associated with the eavesdrop 130 may result in statisticsbeing generated for the “link” used by the secondary audio bud 115.Therefore, the exemplary embodiments refer to link statistics for theeavesdrop 130. However, those skilled in the art will appreciate thatthe eavesdrop may not be a link, connection, communication pathway, etc.as used in a conventional understanding. For example, an explicitconnection (e.g., a piconet) may not be formed between the source device105 and the secondary audio bud 115. In another example, in aconnection, the end devices of the connection typically acknowledge oneanother. However, using the eavesdrop 130, the source device 105 may beunaware of the existence of the secondary audio bud 115. Thus, theeavesdrop 130 being referred to as a link is for illustrative purposesdue to the link statistics that may be generated based on the eavesdropfunctionality. In addition, the eavesdrop 130 is generally enabledbecause the secondary audio bud 115 is aware of the transmissionschedule for the S2B link 120 between the source device 105 and theprimary audio bud 110. This awareness may be based on communicationsbetween the primary audio bud 110 and the secondary audio bud via theB2B link 125.

The source device 105 may be any electronic device capable ofestablishing the S2B link 120. For example, the source device 105 may bea mobile device (e.g., a mobile computing device, a mobile phone, apersonal computer, a cellular phone, a smartphone, a tablet computer, aphablet, a laptop, a VoIP phone, a personal digital assistant, anembedded device, a wearable device, a Cat-M device, a Cat-M1 device, aMTC device, an eMTC device, a peripheral device, another type of anInternet of Things (IoT) device, etc.) or a stationary device (e.g., adesktop terminal). The paired audio device 108 including the primaryaudio bud 110 and the secondary audio bud 115 may be any plurality ofwireless audio output components used together (e.g., ear buds). Theprimary audio bud 110 and the secondary audio bud 115 may be untetheredto the source device 105 as well as to each other. The use of audiorelated devices such as the audio buds is only exemplary. For example,the primary audio bud 110 and the secondary audio bud 115 may also beanother smartphone, a wireless earpiece, a wireless headset, a wirelessdisplay device, a wearable, Bluetooth-enabled hands-free headsets,wireless speakers, intercoms, fitness tracking devices, sensors,automobile sound systems, etc.

In the system 100, the source device 105 and the primary audio bud 110may have a master/subordinate relationship over the S2B link 120.Similarly, the primary audio bud 110 and the secondary audio bud 115 mayhave a master/subordinate (or primary/secondary) relationship over theB2B link 125. However, the master/subordinate relationship is onlyexemplary. According to another exemplary embodiment, the componentsconnected via the short-range communication links may have a mutualrelationship where neither component has a priority (e.g., sharing anequal priority) or neither component has predetermined operations thatmust be performed (e.g., the predetermined operations may have shared orthe duty to perform may be shared). In yet another exemplary embodiment,the master/subordinate relationship may be dynamically set. As will bedescribed further below, according to a sink coordination scheme, theprimary audio bud 110 and the secondary audio bud 115 may coordinate toset the appropriate setting based on current conditions. Thereafter, theselected primary audio bud 110 may establish the S2B link 120 with thesource device 105.

In establishing the short-range communications links (e.g., the S2B link120 or the B2B link 125), the source device 105, the primary audio bud110, and the secondary audio bud 115 may include the necessary hardware,software, and/or firmware to perform conventional operations as well asoperations according to the exemplary embodiments. FIG. 2 shows selectcomponents of the exemplary system 100 of FIG. 1 according to variousexemplary embodiments described herein. FIG. 2 shows the system 100including the source device 105 and the primary sink device 110. Thedescription herein for the primary sink device 110 may also be used todescribe the secondary sink device 115 as the secondary sink device 115may include substantially similar components and functionalities as theprimary sink device 110.

The source device 105 and the primary sink device 110 may be used toexchange data (e.g., audio streaming) over the S2B link 120. The sourcedevice 105 and the primary sink device 110 may include components thatenable this data exchange to be performed in a manner consistent withthe mechanisms according to the exemplary embodiments. As shown in FIG.2, the source device 105 may include a processor 210, a memoryarrangement 215, and a transceiver 220. The source device 105 may alsoinclude further components such as a display device, an input/output(I/O) device, and other components such as a portable power supply, anaudio I/O device, etc. The primary sink device 110 may also includesubstantially similar components such as a processor 250, a memoryarrangement 255, and a transceiver 260 as well as other components.

The processors 210, 250 may be configured to execute a plurality ofengines of the source device 105 and the primary sink device 110,respectively. For example, the engines executed by the processor 210 mayinclude a source link exchange engine 225, a sink identification engine230, a transmit control engine 235, a link stat processing engine 240,and a bud link listening engine 245. Each of these engines 225-245 willbe described in more detail below.

In another example, the engines executed by the processor 250 mayinclude a bud link exchange engine 265, a role switch engine 270, arelay engine 275, a power reduction engine 280, an explicit feedbackengine 285, and an inexplicit feedback engine 290. Each of these engines265-290 will be described in more detail below.

The above described engines each being an application (e.g., a program)executed by the processors 210, 250 is only exemplary. The functionalityassociated with the engines may also be represented as a separateincorporated component of the source device 105 or the primary sinkdevice 110 or may be a modular component coupled to the source device105 or the primary sink device 110, e.g., an integrated circuit with orwithout firmware. For example, the integrated circuit may include inputcircuitry to receive signals and processing circuitry to process thesignals and other information. The engines may also be embodied as oneapplication or separate applications or as part of one or moremultifunctional programs. Accordingly, the applications may beimplemented in a variety of manners in hardware, software, firmware, ora combination thereof. In addition, in some devices, the functionalitydescribed for the processors 210, 250 may be split among two or moreprocessors such as a baseband processor and an applications processor.The exemplary embodiments may be implemented in any of these or otherconfigurations of a device.

The memory arrangements 215, 255 may be a hardware component configuredto store data related to operations performed by the source device 105and the primary sink device 110, respectively. For example, the memoryarrangement 215 may store information link statistics associated withthe primary sink device 110 and/or the secondary sink device 115. Inanother example, the memory arrangement 255 may store the packettransmitted from the source device 105 as well as link statisticsassociated with the primary sink device 110 and/or the secondary sinkdevice 115. The transceivers 220, 260 may be a component of the sourcedevice 105 and the sink device 110, respectively, that enablescommunication with other devices over one or more communicationpathways. For example, the transceivers 220, 260 may enable theBluetooth connection between the source device 105 and the primary sinkdevice 110. The transceivers 220, 260 may therefore be equipped with aBluetooth radio. The transceiver 260 may also enable the Bluetoothconnection between the primary sink device 110 and the secondary sinkdevice 115.

Source Device Engines

The following provides a short description of the engines executed bythe source device 105 according to the exemplary embodiments. The sourcelink exchange engine 225 may select settings and transmit a packet fromthe source device 105 to the primary sink device 110 over the S2B link120. Those skilled in the art will understand the various manners thatmay be used to transmit a packet over the S2B link 120. The source linkexchange engine 225 may receive data from an application executing onthe source device 105 (e.g., an audio streaming application), generate acorresponding packet or plurality of packets, identify transmissionsettings, and transmit the packet over the S2B link 120 using thesettings.

The sink identification engine 230 may identify the sink device in thepaired audio device 108 with which the source device 105 has establisheda connection over the S2B link 120. When the paired audio device 108includes a plurality of sink devices and when these sink devices areconfigured such that any one may act as the primary sink device 110while the remaining ones act as the secondary sink device 115, the S2Blink 120 may be established between the source device 105 and differentones of the sink devices. The sink identification engine 230 maydetermine which of the sink devices is the primary sink device 110. Thesink identification engine 230 may also determine information associatedwith the S2B link 120 (e.g., link statistics) with the identifiedprimary sink device 110.

The transmit control engine 235 may determine transmit settings to beused in transmitting a packet to the primary sink device 110. In a firstexample, the transmission setting may be the transmit power. Arelatively high transmit power results in a first transmission rangewhile a relatively low transmit power results in a second, smallertransmission range in which the packet may be transmitted. The hightransmit power may be selected when a quality of a communication link isrelatively weak while a lower transmit power may be selected when aquality of a communication link is relatively strong. The quality of thecommunication link may be being determined, for example, based on theinformation determined by the sink identification engine 230. Thetransmit control engine 235 may determine the appropriate transmit powerand provide this information to the source link exchange engine 225 fora packet to be transmitted.

In a second example, the transmission setting may be an antenna switchscheme for a single chain radio source device with multiple antennas. Inthis example, the source device 105 may select different antennas totransmit to individual sink devices at different transmit opportunities.As will be described in greater detail below, the source device 105 mayreceive explicit or inexplicit feedback from one or more of the sinkdevices. Based on this feedback, the source device 105 may selectdifferent antennas for different transmit opportunities based on thetransmit control engine 235 determining the appropriate transmissionantenna and providing this information to the source link exchangeengine 225 for a packet to be transmitted.

In a third example, the transmission setting may be a transmit beamforming scheme for a multi-chain radio/antenna source device. In thisexample, the source device 105 may beam form to individual sink devicesat the one or different transmit opportunities. Again, one or more ofthe feedback mechanisms described below may be used as input for thebeam forming transmission setting. Thus, the transmit control engine 235may determine the appropriate beam former and provide this informationto the source link exchange engine 225 for a packet to be transmitted.

In a fourth example, the transmission setting may be a MIMO scheme for amulti-chain radio/antenna source device. For example, the source device105 may transmit independent spatial streams, e.g., a firstantenna/radio chain of the source device transmits left channel audioinformation to a first sink device and a second antenna/radio chain ofthe source device transmits right channel audio information to a secondsink device. Thus, the transmit control engine 235 may determine theappropriate MIMO scheme and provide this information to the source linkexchange engine 225 for a packet to be transmitted.

The link stat processing engine 240 may receive link statisticsassociated with the primary sink device 110 and/or the secondary sinkdevice 115. As will be described in detail below, link statisticsassociated with the primary sink device 110 and/or the secondary sinkdevice 115 may be determined and provided to the source device 105. Thelink stat processing engine 240 may process the link statistics toidentify, for example, a quality of the communication link for theprimary sink device 110 and/or the secondary sink device 115. Based onthis identification, the transmit control engine 235 may then be used todetermine an appropriate transmission setting (e.g., transmit power,MIMO scheme, beam forming scheme, transmit antenna, etc.).

The bud link listening engine 245 may listen to exchanges occurring overthe B2B link 125 to determine link statistics associated with theprimary sink device 110 and/or the secondary sink device 115. The budlink listening engine 245 may process the link statistics to identify,for example, a quality of the communication link for the secondary sinkdevice 115. Based on this identification, the bud link listening engine245 may provide information to the transmit control engine 235 todetermine an appropriate transmission setting (e.g., transmit power,MIMO scheme, beam forming scheme, transmit antenna, etc.).

Sink Device Engines

The following provides a brief description of the engines executed bythe primary sink device 110 according to the exemplary embodiments. Itshould be understood that the secondary sink device 115 may also executesome or all of the same engines. The bud link exchange engine 265 mayselect settings and exchange data between the primary sink device 110and the secondary sink device 115 over the B2B link 125 or the sourcedevice 105 over the S2B link 120. Those skilled in the art willunderstand the various manners that may be used to exchange data overthe B2B link 125 and/or the s2B link 120.

The role switch engine 270 may identify the relationship to be usedbetween the primary sink device 110 and the secondary sink device 115.After determining the link statistics of the primary sink device 110,the role switch engine 270 may also receive link statistics of thesecondary sink device 115. Based on this information, the role switchengine 270 may determine which of the sink devices in the paired audiodevice 108 is to be set as the primary sink device 110 and the secondarysink device 115. Thereafter, the S2B link 120 with the source device 105may be maintained with the same primary sink device 110 or updated witha new primary sink device 110 using any mechanism as those skilled inthe art will understand. Throughout this description, when linkstatistics are used to compare channel conditions between the primarysink device 110 and the source device 105 (e.g., the S2B link 120) andthe secondary sink device 115 and the source device (e.g., the eavesdroplink 130), it should be understood that any link statistic may be usedfor this comparison. In addition, when determining a relative quality ofthe links, a difference threshold of the link statistics may be used toidentify a weaker or stronger link.

The relay engine 275 may determine a packet that was properly receivedby one of the primary sink device 110 or the secondary sink device 115that is to be relayed to the other one of the primary sink device 110 orthe secondary sink device 115. The relay engine 275 may utilize the budlink exchange engine 265 for the packet to be relayed over the B2B link125. Thus, in the scenario where only one of the sink devices of thepaired audio device 108 properly receives the packet, the relay engine275 may be used to relay the packet to the sink device that did notreceive the packet.

The power reduction engine 280 may dynamically adjust a transmit powerused by the primary sink device 110 for transmissions to the sourcedevice 105. Using the bud link exchange engine 265, the power reductionengine 280 may receive link statistics from the secondary sink device115. The power reduction engine 280 may compare the link statistics ofthe primary sink device 110 to the link statistics of the secondary sinkdevice 115 to determine whether the eavesdrop 130 of the secondary sinkdevice 115 is weaker than the S2B link 120 of the primary sink device110 for receiving packets from the source device 105. In instances wherethe secondary sink device 115 has the weaker connection, the powerreduction engine 280 may cause the primary sink device 110 to reducetransmit power when transmitting data to the source device 105 over theS2B link 120. A result of the transmit power reduction by the primarysink device 110 may be the source device 105 determining that the sourcedevice 105 transmit power should be increased. Thus, although theprimary sink device 110 may not need the source device 105 to increasethe transmit power, the increased transmit power may allow the secondarysink device 115 to increase the probability of receiving the packet fromthe source device 105.

The explicit feedback engine 285 may gather link statistic informationfor the primary sink device 110 and the secondary sink device 115 andgenerate a packet or packets including the link statistic information(hereinafter referred to as “link statistic packet”) that is to betransmitted to the source device 105. The secondary sink device 115 maytransmit the link statistics to the explicit feedback engine 285 of theprimary sink device 110. The explicit feedback engine 285 may determinelink statistics for the primary sink device 110. The explicit feedbackengine 285 may generate the link statistic packet and transmit the linkstatistic packet to the source device 105 over the S2B link 120. Usingthis information, the source device 105 may select appropriate settingsto transmit subsequent packets so increase the probability that both theprimary sink device 110 and the secondary sink device 115 receive thepacket.

The inexplicit feedback engine 290 may gather link statistic informationof the primary sink device 110 and the secondary sink device 115 andincorporate the link statistic information in packets that are bound forthe source device 105. In this example, there may not be an explicitpacket designated for link statistics feedback. Rather, the linkstatistics may be included in available space in other packets, (e.g.,control packets, data packets, etc.) that are sent to the source device105 by the primary sink device 110. The source device 105 may use thisdata in a similar manner as described above for the explicit feedbackdata.

Sink Coordination Mechanisms

As discussed above, the sink coordination mechanisms are configured suchthat the sink devices perform operations that are transparent to thesource device to increase a likelihood that the packet is received byeach of the sink devices. A first exemplary sink coordination mechanismutilizes a role switch performed by the paired audio device 108. Asecond exemplary sink coordination mechanism utilizes a data relaybetween the primary sink device 110 and the secondary sink device 115. Athird exemplary sink coordination mechanism utilizes a power reductionoperation for packets bound for the source device 105. A fourthexemplary sink coordination mechanism utilizes a transmit coordinationscheme for transmitting acknowledgements to the source device 105.

The first sink coordination mechanism utilizes a role switch performedby the paired audio device 108. FIG. 3 shows a sink roll switch scenario300 and corresponding mechanism for the sink devices 110, 115 to receivea packet according to various exemplary embodiments described herein.FIG. 3 shows exemplary circumstances for which the first sinkcoordination mechanism may be used. As illustrated, the source device105, the primary sink device 110, and the secondary sink device 115 ofFIG. 1 are shown with various transmissions.

The sink roll switch scenario 300 shows a first state 305 that maytrigger use of the first sink coordination mechanism. As illustrated,the source device 105 may establish the S2B link 120 with the sinkdevice 110. In the first state 305, the sink device 110 may be theprimary sink device while the sink device 115 may be the secondary sinkdevice. Based on this relationship, the source device 105 may transmit apacket to the primary sink device 110 in a transmission 310. Thesecondary sink device 115 may use the eavesdrop 130 to attempt toreceive the packet (illustrated as an eavesdrop 315). In this scenario,it may be considered that the primary sink device 110 may have a strongcommunication link with the source device 105 while the secondary sinkdevice 115 may have a weak communication link with the source device105. Thus, the primary sink device 110 may receive the packet whilesecondary sink device 115 may not receive the packet. The secondary sinkdevice 115 may utilize the B2B link 125 to transmit a NACK in atransmission 325 to the primary sink device 110 to indicate the packetwas not received. The primary sink device 110 may then use the S2B link120 to transmit a NACK in a transmission 320 to the source device 105 toindicate that the packet was not successfully received by all sinkdevices.

In light of the conditions experienced in the first state 305, theprimary sink device 110 and the secondary sink device 115 may utilizethe first sink coordination mechanism that may include each of theprimary sink device 110 and the secondary sink device 115 tracking linkstatistics for the communication link with the source device 105. Thesecondary sink device 115 may utilize the B2B link 125 to transmit thelink statistics to the primary sink device 110. The secondary sinkdevice 115 may transmit the link statistics at various times (e.g.,continuously, periodically at predetermined intervals, when an eventoccurs, when a predetermined amount of change in the link statistics isregistered, etc.). Based on the link statistics for the secondary sinkdevice 115 and its own link statistics, the primary sink device 110 maydetermine which of the two sink devices 110, 115 that should be set asthe primary for subsequent packet transmission from the source device105. For example, the primary sink device 110 may designate the sinkdevice having a weaker communication link to be the primary sink device.In one example, the sink device having a lower RSSI value for thecommunication link may be designated as primary. It should be understoodthat any link statistic may be used singularly or in combination withother link statistics to determine the weaker communication link. Thus,in the first state 305, the secondary sink device 115 may be identifiedas having the weaker communication link. Since the sink device havingthe weaker communication link is not currently set as the primary sinkdevice, the primary sink device 110 and the secondary sink device 115may perform a role switch operation over the B2B link 125 so that thesink device 110 becomes the secondary and the sink device 115 becomesthe primary. Those skilled in the art will understand that to accomplishthe role switch, the current S2B link 120 is disconnected and the sinkdevice 115 (new primary) may establish a new S2B link 120 with thesource device 105 while the sink device 110 (new secondary) uses theeavesdrop 130.

This may result in the second state 350 in which the source device 105has the S2B link 120 with the new primary sink device 115 and the newsecondary sink device 110 uses the eavesdrop 130. Assuming substantiallysimilar conditions as the first state 305, in the second state 350, thesource device 105 may use the RSSI from the new primary sink device 115to select settings such that the packet is more likely to be received bythe new primary sink device 115. For example, based on communicationsbetween the source device 105 and the new primary sink device 115, thesource device 105 may determine a perceived RSSI for the new primarysink device 115. The source device 105 may then select to increase atransmit power so that the new primary sink device 115 is likely toreceive the packet, leading to the second state 350. As illustrated inthe second state 350, the source device 105 transmits a packet in atransmission 355 to the new primary sink device 115 over the S2B link120. The new secondary sink device 110 uses the eavesdrop 130(illustrated as an eavesdrop 360) and also receives the packet. Sincethe new secondary sink device 110 was already capable of receiving thepacket based on settings used by the source device 105 in the firststate 305, the new transmission settings will likely allow the newsecondary sink device 110 to receive the packet. The new secondary sinkdevice 110 may then transmit an ACK in a transmission 370 over the B2Blink 125. The new primary sink device 115 may determine that both thenew primary sink device 115 and the new secondary sink device 110 havereceived the packet such that an ACK is transmitted in a transmission365 over the S2B link 120 to the source device 105.

By using the first sink coordination mechanism, the sink devices 110,115 may passively or transparently cause the source device 105 to adjusttransmission settings to make it more likely that both sink devices 110,115 receive the transmitted packets. This approach may allow the sourcedevice 105 that has a larger capacity battery than the sink devices 110,115 to utilize its power to allow the packet to be received by the sinkdevices 110, 115 rather than utilizing more power by the sink devices110, 115 because of increased receiver sensitivity or increased relayingof packets using the B2B link 125.

The second sink coordination mechanism utilizes a data relay between theprimary sink device 110 and the secondary sink device 115. FIG. 4 showsa sink relay scenario 400 and corresponding mechanism for the sinkdevices 110, 115 to receive a packet according to various exemplaryembodiments described herein. FIG. 4 shows exemplary circumstances forwhich the second sink coordination mechanism may be used. The sink relayscenario 400 shows a first state 405 that may trigger use of the secondsink coordination mechanism. The first state 405 of the sink relayscenario 400 may be substantially similar to the first state 305 of thesink roll switch scenario 300. Thus, the communications 410-425 aresimilar to the communications 310-325 and will not be described further.

In light of the conditions experienced in the first state 405, theprimary sink device 110 and the secondary sink device 115 may utilizethe second sink coordination mechanism that includes using the B2B link125 to relay the packet that was properly received by the primary sinkdevice 110 to the secondary sink device 115. For example, using anavailable remaining time window allocated for transmitting a packet fromthe source device 105 to the primary sink device 110 (e.g., an initialtransmission attempt or a retransmission attempt), the relay operationof the second sink coordination mechanism may be used. The second sinkcoordination mechanism may allow for further opportunities for thesecondary sink device 115 to receive the packet.

The sink relay scenario 400 may then lead to the second state 450. Thesecond state 450 may include substantially similar aspects as the firststate 405. The source device 105 may transmit a packet to the primarysink device 110 in a transmission 455. The secondary sink device 115 mayuse the eavesdrop 130 (illustrated as an eavesdrop 460) to attempt toreceive the packet but may be incapable of receiving the packet.However, in the second state 450, the primary sink device 110 and thesecondary sink device 115 may use the relay operation of the second sinkcoordination mechanism. The packet that was received by the primary sinkdevice 110 may be transmitted to the secondary sink device 115 in atransmission 475 using the B2B link 125. If the secondary sink device115 successfully receives the packet, the secondary sink device willtransmit an ACK to the primary sink device 110 in a transmission 470. Ifthe secondary sink device in not successful in receiving the packet, thesecondary sink device will transmit a NACK to the primary sink device110 in the transmission 470. The primary sink device 110 may receive thetransmission 470 and transmit an appropriate ACK or NACK in atransmission 465 to the source devoice 105.

The above exemplary embodiment and sink relay scenario 400 relates tothe primary sink device 110 performing the relay operation of the secondsink coordination mechanism based on the primary sink device 110receiving the packet while the secondary sink device 115 does notreceive the packet. However, this set of conditions for the sink relayscenario 400 is only exemplary. The relay operation of the second sinkcoordination mechanism may also be used in a reverse direction. Forexample, the secondary sink device 115 may receive the packet while theprimary sink device 110 does not receive the packet. In such acondition, the relay operation of the second sink coordination mechanismmay still be used and a transmission including the packet may betransmitted over the B2B link 125 from the secondary sink device 115 tothe primary sink device 110.

By using the second sink coordination mechanism, the primary sink device110 and the secondary sink device 115 may be capable of receiving thepacket from the source device 105 with more opportunities usingoperations performed by the primary sink device 110 and the secondarysink device 115. By performing the second sink coordination mechanismusing the primary sink device 110 and the secondary sink device 115, themechanism may appear transparent to the source device 105. This approachmay allow the source device 105 to retain more power in its battery toincrease the battery life of the source device 105. Furthermore,increased opportunities to transmit the packet increases a probabilitythat the packet is received by the primary sink device 110 and thesecondary sink device 115 to reduce audio glitches.

The various mechanisms of the exemplary embodiments may be used in anindividual manner but may also be used in combination. For example, thefirst sink coordination mechanism may be used with the second sinkcoordination mechanism. A factor that may determine whether onemechanism is to be used is a remaining battery life of the individualcomponents. In a first exemplary set of conditions, the batteries of oneor both of the sink devices 110, 115 may fall below a predeterminedpower level. In this situation, it may be more effective to use thesource device 105 to transmit the packet with an increased probabilityof reception. Therefore, the role switch operation of the first sinkcoordination mechanism may be used that causes the source device 105 to,for example, increase the transmit power. In a second exemplary set ofconditions, the sink devices 110, 115 may have a sufficient power levelin their batteries while the battery level of the source device 105 mayfall below a predetermined power level. In this situation, the it may bemore effective to use the sink devices 110, 115 to provide furtheropportunities to transmit the packet using the relay operation of thesecond sink coordination.

The third sink coordination mechanism utilizes a power reductionoperation for packets bound for the source device 105, thereby causingthe source device 105 to increase the transmit power. FIG. 5 shows asink transmit power reduction scenario 500 and corresponding mechanismfor the sink devices 110, 115 to receive a packet according to variousexemplary embodiments described herein. FIG. 5 shows exemplarycircumstances for which the third sink coordination mechanism may beused. The sink transmit power reduction scenario 500 shows a first state505 that may trigger use of the third sink coordination mechanism. Thefirst state 505 of the sink transmit power reduction scenario 500 may besubstantially similar to the first state 305 of the sink roll switchscenario 300. Thus, the communications 510-525 are similar to thecommunications 310-325 and will not be described further.

In light of the conditions experienced in the first state 505, theprimary sink device 110 and the secondary sink device 115 may utilizethe power reduction operation of the third sink coordination mechanism.The primary sink device 110 may use various approaches to implement thepower reduction operation. In a first approach, the third sinkcoordination mechanism may include each of the primary sink device 110and the secondary sink device 115 tracking link statistics for thecommunication link with the source device 105 in a manner substantiallysimilar to the first sink coordination mechanism. The secondary sinkdevice 115 may utilize the B2B link 125 to transmit the link statisticsof the secondary sink device 115 to the primary sink device 110. Whenthe primary sink device 110 receives the link statistics of thesecondary sink device 115, the primary sink device 110 may determinewhether the communication link of the secondary sink device 115 isweaker than the communication link of the primary sink device 110. Theweaker communication link may be causing the secondary sink device 115to not receive the packet being transmitted over the S2B link 120. Theprimary sink device 110 may determine that the source device 105 shouldmodify its settings used to transmit the packet so that the secondarysink device 115 may receive the packet. In a second approach, the thirdsink coordination mechanism may utilize the NACK in the transmission 525to assume that the secondary sink device 115 has a weaker communicationlink. In a third approach, a combination of the link statistics and theindication may be used. Once the secondary sink device 115 is determinedto have the weaker communication link, the primary sink device 110 mayadjust its settings to transmit data to the source device 105 over theS2B link 120. For example, the primary sink device 110 may reduce thetransmit power for the transmission 520 or subsequent transmissions. Thereduction in the transmit power by the primary sink device 110 mayresult in the source device 105 not receiving the transmissions or thesource device 105 receiving the transmissions at a lower power level(e.g., the source device 105 perceiving a lower average RSSI for theprimary sink device 110). In either case, this will cause the sourcedevice 105 to increase the transmit power the source device 105 is usingfor transmissions.

The sink transmit power reduction scenario 500 may then lead to thesecond state 555. In the second state 555, the source device 105 maytransmit a packet to the primary sink device 110 in a transmission 560using updated settings (e.g., higher transmit power) in view of theresult from the first state 505 (e.g., the lower transmit power of theprimary sink device 110). The updated settings to transmit the packetmay also result in the secondary sink device 115 using the eavesdrop 130(illustrated as an eavesdrop 565) to receive the packet. An ACK may thenbe transmitted from the secondary sink device 115 to the primary sinkdevice 110 in a transmission 575 over the B2B link 125. The primary sinkdevice 110 may then transmit an ACK in a transmission 570 to the sourcedevice 105 indicating that both the primary sink device 110 and thesecondary sink device 115 received the packet.

By using the third sink coordination mechanism, the primary sink device110 and the secondary sink device 115 may be capable of transparentlymodifying the settings used by the source device 105 to transmit packetsso that both the primary sink device 110 and the secondary sink device115 have an increased probability of receiving the.

In the above examples, the sink coordination mechanisms were triggeredby the secondary sink device 115 not receiving a transmitted packet.However, other triggers may be used to implement the sink coordinationmechanisms. For example, even if a packet is received by the secondarysink device 115, the link statistics may trigger one or more of the sinkcoordination mechanisms.

The fourth exemplary sink coordination mechanism utilizes a transmitcoordination scheme for transmitting acknowledgements to the sourcedevice 105. FIG. 6 shows a secondary sink ACK scenario 600 andcorresponding mechanism for the sink devices 110, 115 to receive apacket according to various exemplary embodiments described herein. FIG.6 shows exemplary circumstances for which the fourth sink coordinationmechanism may be used. As illustrated, the source device 105, theprimary sink device 110, and the secondary sink device 115 of FIG. 1 areshown with various transmissions.

The secondary sink ACK scenario 600 shows a first state 605 that maytrigger use of the fourth sink coordination mechanism. Similar to theabove described scenarios, the sink device 110 may be the primary sinkdevice while the sink device 115 may be the secondary sink device. Thesource device 105 may transmit a packet to the primary sink device 110in a transmission 610. The secondary sink device 115 may use theeavesdrop 130 to attempt to receive the packet (illustrated as aneavesdrop 615). In this scenario, it may be considered that both theprimary sink device 110 and the secondary sink device 115 successfullyreceived the packet. The secondary sink device 115 may utilize the B2Blink 125 to transmit an ACK in a transmission 625 to indicate the packetwas successfully received. The primary sink device 110 may then use theS2B link 120 to transmit an ACK in a transmission 620 to the sourcedevice 105 to indicate the packet was successfully received by all sinkdevices.

Throughout this description, when it is stated that the source device105 receives an ACK indicating that a packet was successfully receivedby all sink devices, this does not necessarily mean that the ACKincludes an indication that identifies all the sink devices. Rather,because the source device 105 receives an ACK from the primary sinkdevice 110, the source device 105 may assume that all of the secondarysink devices have successfully received the packet because, as statedabove, the source device 105 may not even be aware of all the sinkdevices. Similarly, when the source device receives a NACK, it may notindicate the exact sink device that did not receive the packet, justthat one of the sink devices did not receive the packet.

In this exemplary secondary sink ACK scenario 600, the source device 105did not successfully receive the transmission 620 (including the ACK).There may be various reasons why the packet transmission 610 wassuccessful but the ACK transmission 620 was not successful over the samecommunication link. For example, radio conditions may have changed, atemporary interferer may have appeared, the devices may have movedrelative to each other, etc. In any case, under normal circumstances,when the source device 105 does not receive an ACK indicating the sinkdevices successfully received the packet, the source device 105 willattempt to retransmit the packet for as many times as needed (or aslimited by retransmission attempts) in order to receive an ACKindicating the sink devices received the packet. However, this couldlead to unnecessary increases in the transmit power by the source device105 and to multiple retransmission attempts that are not needed becausethe sink devices actually received the packet.

To correct this issue, the fourth mechanism utilizes a transmitcoordination scheme between the sink devices 110 and 115 fortransmitting acknowledgements to the source device 105. In this example,the secondary sink device 115 uses another eavesdrop operation 630 tolisten to the transmission 620 sent from the sink device 110 to thesource device 105. Since the secondary sink device 115 knows that itreceived the packet successfully and that the primary sink device 110sent an ACK to the source device 105, the secondary sink device 115understands that both sink devices 110 and 115 successfully received thepacket.

However, because the source device 105 did not receive the ACKtransmission 620, the source device 105 will attempt a firstretransmission attempt as shown in the second state 650. The sourcedevice 105 may retransmit the packet to the primary sink device 110using a transmission 660, the secondary sink device 115 may use theeavesdrop 130 to attempt to receive the packet (illustrated as aneavesdrop 665). In this scenario, it may be considered that both theprimary sink device 110 and the secondary sink device 115 successfullyreceived the packet (either in the original transmission attempt or theretransmission attempt). The secondary sink device 115 may utilize theB2B link 125 to transmit an ACK in a transmission 675 to indicate thepacket was successfully received. However, in this scenario, instead ofthe primary sink device 110 sending the ACK transmission to the sourcedevice 105, the secondary sink device 115 sends a transmission 670including the ACK to the source device 105. In this manner, when thesecondary sink device 115 may have a better communication path to thesource device 105, the secondary sink device may transmit the ACK whenthe first transmission of the ACK by the primary sink device 110 fails.When the source device 105 receives the transmission 670 including theACK, the source device will understand that the sink devices havereceived the packet and will discontinue any additional retransmissions.

It should be understood that there should be an agreement between thesink devices 110 and 115 that the secondary sink device 115 willtransmit the ACK instead of the primary sink device 110. This agreementmay be based on preprogramming where if the first ACK transmission 620fails, the secondary sink device 115 will perform a second (or anysubsequent) ACK transmission(s) 670. In another example, a communicationbetween the sink devices 110 and 115 may be used to determine the sinkdevice 110 or 115 that will send the ACK transmission 670. For example,this information may be exchanged in the transmission 675. It shouldalso be understood that since the source device 105 may be unaware ofthe existence of the secondary sink device 115, when the secondary sinkdevice 115 transmits the ACK transmission 670, the secondary sink device115 may use information such as the address of the primary sink device110 in the transmission so that the source device 105 identifies thetransmission 670 to be coming from the primary sink device 110 (eventhough it is actually coming from the secondary sink device 115).Finally, it should also be understood that the primary sink device 110may, at the same time, also send a transmission with the primary ACK inthe normal manner, e.g., there may be two transmissions simultaneouslyfrom the primary sink device 110 and secondary sink device 115 thatinclude the primary ACK.

The fourth exemplary sink coordination mechanism may also havealternative exemplary embodiments. In a first example of an alternativeembodiment, the secondary sink device 115, in addition to sending thetransmission 670 with the primary ACK in the designated transmissionslot for the ACK, may also send a further transmission with a secondaryACK at the expected source slot boundary (e.g., near the boundary of theBluetooth slot designated for transmission of the packet). This furthertransmission may be sent when, for example, the source device 105 hasonly one simultaneous receive antenna or cannot perform successivecancellation methods using more than one antenna. Another conditionwhere this further transmission may be used is when the channelconditions between the secondary sink device 115 and the source device105 are significantly better than the channel conditions between theprimary sink device 110 and the source device 105 (e.g., greater than 20dB). This embodiment may be applied on its own or in combination withthe other conditions described above.

In another example, the further transmission may be sent when the sourcedevice 105 has two or more simultaneous receive chain receptions and canuse successive cancellation methods to lock down on a strongest one ofthe signals (e.g., transmission 670 or the further transmission). In astill further example, the further transmission may be sent when thesource device 105 supports maximum ratio combining (MRC) or rakereceiving, where the receive power from two separate transmissions maybe combined.

In a second example of an alternative embodiment of the fourth sinkcoordination mechanism, the secondary sink device 115, in addition tosending the transmission 670 with the primary ACK in the designatedtransmission slot, may also send a further transmission with a secondaryACK prior to the designated transmission slot for the transmission 670.This earlier transmission may aid the source device 105 to lock on thestronger signal that is coming from the secondary sink device 115. Inthis exemplary embodiment, the further transmission may be at apredetermined time that is prior to the designated transmission slot forthe ACK and the source device 105 may open its reception window earlierto receive the further transmission. This early opening of the receptionwindow by the source device 105 may be negotiated between the devices.

In a third example of an alternative embodiment of the fourth sinkcoordination mechanism, the secondary sink device 115, instead ofsending the transmission 670 with the primary ACK in the designatedtransmission slot, may send the transmission 670 including the primaryACK after the designated transmission slot (e.g., in the interframespace (IFS) after the designated transmission slot such as at a halfslot start boundary). As described above, the primary sink device 110may also be transmitting the primary ACK in the designated transmissionslot and each of these alternative exemplary embodiments of the fourthsink coordination mechanisms may aid the source device 105 in receivingthe primary ACK that is sent by either the secondary sink device 115 orthe primary sink device 110.

Sink-Source Coordination Mechanisms

The sink-source coordination mechanisms are configured such that thesink devices perform operations to provide information to the sourcedevice to modify the transmission settings that increase a likelihoodthat the packet is received by each of the sink devices. The exemplaryembodiments may provide a plurality of sink-source coordinationmechanisms. As will be described below, a first sink-source coordinationmechanism utilizes an explicit protocol to provide link statistics ofthe primary sink device 110 and the secondary sink device 115 to thesource device 105. A second sink-source coordination mechanism utilizesan inexplicit protocol to provide link statistics of the primary sinkdevice 110 and the secondary sink device 115 to the source device 105.

The first sink-source coordination mechanism utilizes an explicitprotocol to provide link statistics of the primary sink device 110 andthe secondary sink device 115 to the source device 105. FIG. 7 shows anexplicit link statistic scenario 700 and corresponding mechanism for thesink devices 110, 115 to receive a packet according to various exemplaryembodiments described herein. FIG. 7 shows exemplary circumstances forwhich the first sink-source coordination mechanism may be used. Asillustrated, the source device 105, the primary sink device 110, and thesecondary sink device 115 of FIG. 1 are shown with varioustransmissions.

The explicit link statistic scenario 700 shows a first state 705 thatmay trigger use of the first sink-source coordination mechanism. Asillustrated, the source device 105 may establish the S2B link 120 withthe primary sink device 110. The source device 105 may transmit a packetto the primary sink device 110 in a transmission 710. The secondary sinkdevice 115 may use the eavesdrop 130 (illustrated as an eavesdrop 715)to receive the packet. Again, in this example, the primary sink device110 may receive the packet and the secondary sink device 115 may notreceive the packet. The secondary sink device 115 may utilize the B2Blink 125 to transmit a NACK in a transmission 725 to indicate the packetwas not received. The primary sink device 110 may receive thetransmission 725 and may transmit a NACK to the source device 105 in atransmission 720 over the S2B link 120 indicating that all the sinkdevices 110, 115 have not received the packet.

In light of the conditions experienced in the first state 705, theprimary sink device 110 and the secondary sink device 115 may use thefirst sink-source coordination mechanism. The secondary sink device 115may send a transmission 730 to the primary sink device 110 includinglink statistics associated with the eavesdrop 130 communication linkbeing experienced by the secondary sink device 115. The transmission 730may be a link statistic packet that is a dedicated packet used forsending the link statistics of the secondary sink device 115. Forexample, the link statistic packet may be a specifically designatedpacket that is generated and transmitted for the purpose of providingthe link statistics. The transmission 730 may be encoded (e.g., sourcecoding) to reduce a number of bits used to transmit the link statisticpacket over the B2B link 125. The secondary sink device 115 maydetermine the link statistics, generate the link statistic packet,and/or transmit the link statistic packet at various times. For example,the secondary sink device 115 may perform one or more of theseoperations at predetermined time intervals, at random time intervals,when an event is registered (e.g., a change in the link statistics,failure to receive a packet, etc.), etc.

The primary sink device 110 may also determine link statistics for thecommunication link with the source device 105 (e.g., the S2B link 120).Thus, when the primary sink device 110 receives the transmission 730,the primary sink device 110 may generate a further link statistic packetincluding the link statistics of both the primary sink device 110 andthe secondary sink device 115. The primary sink device 110 may transmitthe further link statistic packet in a transmission 735 to the sourcedevice 105. Similar to the link statistic packet transmitted by thesecondary sink device 115, the further link statistic packet may be adedicated packet used for the link statistics of the primary sink device110 and the secondary sink device 115. The link statistics may includespecific values for channel parameters (e.g., RSSI, BLER, channelestimates, etc.) and may also include status information (e.g., previouspacket was received/not received by sink).

Upon receiving the further link statistic packet, the source device 105may process the link statistic information. Based on the respective linkstatistic information of the primary sink device 110 and the secondarysink device 115, the source device 105 may determine appropriatesettings to be used in transmitting subsequent packets. Therefore, whenthe link statistics of the secondary sink device 115 indicate that thepacket is incapable of being received (as is the case in the state 705),the source device 105 may, for example, increase a transmit power forsubsequent packets, alter beam forming or MIMO settings, etc.

The explicit link statistic scenario 700 may then lead to the secondstate 750 where the source device 105 may have modified its settingsbased on the link statistics received in the transmission 735. Thesecond state 750 may include substantially similar aspects as the firststate 705. For example, the source device 105 may transmit a packet tothe primary sink device 110 in a transmission 755. The secondary sinkdevice 115 may use the eavesdrop 130 (illustrated as an eavesdrop 760)to receive the packet. Upon receiving the packet using the eavesdrop130, the secondary sink device 115 may transmit an ACK in a transmission770 using the B2B link 125. The primary sink device 110 may receive thetransmission 770 and generate an ACK to be transmitted in a transmission765 to indicate both the primary sink device 110 and the secondary sinkdevice 115 received the packet. In addition, the link statisticinformation may continue to be provided in the dedicated link statisticpacket. For example, the secondary sink device 115 may transmit the linkstatistic information in a link statistic packet via a transmission 775to the primary sink device 110. Upon receiving the transmission 775, theprimary sink device 110 may transmit the link statistic information ofthe primary sink device 110 and the secondary sink device 115 in afurther link statistic packet via a transmission 780 to the sourcedevice 105. In this manner, the source device 105 may continue to modifyits settings according to the current conditions being experienced bythe primary sink device 110 and the secondary sink device 115.

As described above, upon receiving the link statistics, the sourcedevice 105 may alter transmission settings, e.g., via the transmitcontrol engine 235. In a first example, the setting that may be alteredis the transmit power of the source device 105.

In a second example, the transmit control engine 235 may alter the beamforming setting of the source device 105. For example, the source device105 may have two or more radio cores. Based on the received linkstatistics, the source device 105 may alter the beam forming settings ofthe source device 105. For example, the beam forming setting may beinitially set to beam form to/from both the primary sink device 110 andthe secondary sink device 115. However, based on the link statistics,the beam forming setting may be altered to beam form to a specific oneof the primary sink device 110 or the secondary sink device 115. Toprovide a specific example, if the link statistics as described aboveindicate that the secondary sink device 115 did not receive the packet,the transmit control engine 235 may alter the beam forming setting forthe first retransmission such that the beamforming is directed at thesecondary sink device 115 so that there is a greater chance thesecondary sink device 115 receives the packet since the primary sinkdevice 105 has already received the packet.

In a third example, the transmit control engine 235 may alter the MIMOsettings of the source device 105. For example, the source device 105may implement a spatial multiplexing scheme to/from one or both of theprimary sink device 110 and/or the secondary sink device 115 based onthe link statistics.

The above exemplary implementation for the first sink-sourcecoordination mechanism addresses the explicit link statistic scenario700 where the secondary sink device 115 does not receive the packetusing the eavesdrop 130 and the source device 105 alters thetransmission settings for subsequent packets. However, the firstsink-source coordination mechanism may also be used as a general,dynamic determination for the settings used by the source device 105that continuously controls the transmission settings by balancingvarious considerations. For example, there may be a priority to haveboth the primary sink device 110 and the secondary sink device 115 toreceive the packet. Thus, power consumption may become an ancillaryconsideration and the transmit power may be increased. In anotherexample, when both the primary sink device 110 and the secondary sinkdevice 115 receive the packet, different considerations may takepriority such as power conservation on the source device 105.Accordingly, the first sink-source coordination mechanism may also beused to adjust the settings of the source device 105 for subsequentpackets by considering this factor. For example, the transmit power maybe lowered if the current conditions allow for this modified setting.For example, a historical view may show that a previous number ofpackets was successfully received by both the primary sink device 110and the secondary sink device 115 to indicate that the transmit powermay be re-evaluated.

By using the first sink-source coordination mechanism, the primary sinkdevice 110 and the secondary sink device 115 may be capable of providinginformation to the source device 105 so that the source device 105 maymodify the settings used to transmit subsequent packets so that both theprimary sink device 110 and the secondary sink device 115 have anincreased probability of receiving the packet. By performing the firstsink-source coordination mechanism, the mechanism may allow forexplicitly provided link statistics and more types of link statistics tobe provided to the source device 105.

The various mechanisms of the exemplary embodiments may be used in anindividual manner but may also be used in combination. Accordingly, thefirst sink-source coordination mechanism may be used with the abovedescribed sink coordination mechanisms. In a first example, the firstsink-source coordination mechanism may be used with the second sinkcoordination mechanism (e.g., the relaying mechanism) such that a packetreceived by the primary sink device 110 may be transmitted (e.g., in atransmission 475) to the secondary sink device 115. A factor that maydetermine whether this combination may be used is a remaining batterylife of the source device 105. Thus, to conserve power on the battery ofthe source device 105, the second sink coordination mechanism may alsobe used with the first sink-source coordination mechanism. In thisexample, while the source device 105 is receiving the link statistics,the source device 105 may not increase the transmit power because of alow battery level, but rather the sink devices 110, 115 will use therelay mechanism. However, if the battery level of the source device 105is above a threshold, the source device 105 may increase the transmitpower alleviating the need for the sink devices 110, 115 to use therelaying mechanism.

In a second example, the first sink-source coordination mechanism (e.g.,explicit link statistics) may be used with the third sink coordinationmechanism such that the primary sink device 110 requests the sourcedevice 105 to increase the source transmit power by reducing a transmitpower used by the primary sink device 110. These examples are not meantto be exhaustive, but are merely used to illustrate that the varioussink-source coordination mechanisms and the sink coordination mechanismsmay be used in various combinations, or by themselves, to accomplish thegoals of increasing the likelihood of success of the sink devicesreceiving the transmissions with the least amount of energy expended bythe devices.

The second sink-source coordination mechanism utilizes an inexplicitprotocol to provide link statistics of the primary sink device 110 andthe secondary sink device 115 to the source device 105. FIG. 8 shows aninexplicit link statistic scenario 800 and corresponding mechanism forthe sink devices 110, 115 to receive a packet according to variousexemplary embodiments described herein. FIG. 8 shows exemplarycircumstances for which the second sink-source coordination mechanismmay be used. As illustrated, the source device 105, the primary sinkdevice 110, and the secondary sink device 115 of FIG. 1 are shown withvarious transmissions.

The inexplicit link statistic scenario 800 shows a first state 805 thatmay trigger use of the second sink-source coordination mechanism. Theinexplicit link statistic scenario 800 may be substantially similar tothe explicit link statistic scenario 700. For example, the source device105 may establish the S2B link 120 with the primary sink device 110 anda packet may be transmitted to the primary sink device 110 in atransmission 810. The secondary sink device 115 may use the eavesdrop130 (illustrated as an eavesdrop 815) to attempt to receive the packetbut may not receive the packet. The secondary sink device 115 mayutilize the B2B link 125 to transmit a NACK in a transmission 825 to theprimary sink device 110. The primary sink device 110 may receive thetransmission 825 and generate a NACK to be transmitted to the sourcedevice 105 in a transmission 820 over the S2B link 120 to indicate thatall of the sink devices 110, 115 did not receive the packet.

The second source-sink coordination mechanism may also provide linkstatistics of the primary sink device 110 and the secondary sink device115 to the source device 105. However, rather than a link statisticpacket that is dedicated for this purpose, the second source-sinkcoordination mechanism may extend a packet frame or repurpose designatedbits in a packet that is normally transmitted over the B2B link 125and/or the S2B link 120 to store the link statistics information. Inusing the second sink-source coordination mechanism, the secondary sinkdevice 115 may utilize the B2B link 125 to incorporate the linkstatistic data in the transmission 825 (e.g., in a remaining portion ofthe transmission 825 that is empty) or any other transmission on the B2Blink 125. Like the link statistic packet, the secondary sink device 115may determine the link statistics, generate the link statistic data,and/or transmit the transmission 825 that includes the link statisticdata at various times. However, the transmission 825 with the linkstatistic data may be transmitted at times when the transmission 825would normally be transmitted (e.g., when an ACK or NACK indication isto be transmitted). The primary sink device 110 may also determine linkstatistics for the communication link with the source device 105 (e.g.,the S2B link 120). Thus, when the primary sink device 110 receives thetransmission 825, the primary sink device 110 may generate further linkstatistic data and include the link statistics of both the primary sinkdevice 110 and the secondary sink device 115 in the transmission 820 orany other transmission over the S2B link 120.

Upon receiving the transmission 820, the source device 105 may unpackagethe data and process the link statistic data to determine the linkstatistic information of the primary sink device 110 and the secondarysink device 115. The source device 105 may then perform substantiallysimilar operations as performed by the source device 105 utilizing thefirst sink-source coordination mechanism, such as determining theappropriate settings to be used in transmitting subsequent packets.Therefore, when the link statistics of the secondary sink device 115indicate that the packet is incapable of being received (as is the casein the state 805), the source device 105 may, for example, increase atransmit power for subsequent packets, alter the beam forming settings,alter the MIMO settings, etc.

The inexplicit link statistic scenario 800 may then lead to the secondstate 850. For example, the source device 105 may have modified itssettings based on the link statistics received in the transmission 820.The second state 850 may include substantially similar aspects as thefirst state 805. For example, the source device 105 may transmit apacket to the primary sink device 110 using a transmission 855. Thesecondary sink device 115 may use the eavesdrop 130 (illustrated as aneavesdrop 860) to receive the packet. Upon receiving the packet usingthe eavesdrop 130, the secondary sink device 115 may transmit an ACK ina transmission 870 using the B2B link 125. The transmission 870 may alsoinclude the link statistics of the secondary sink device 115. Theprimary sink device 110 may receive the transmission 870 and generate anindication of an ACK to be transmitted as a transmission 865 that boththe primary sink device 110 and the secondary sink device 115 receivedthe packet. The transmission 865 may also include the link statistics ofthe primary sink device 110 and the secondary sink device 115. In thismanner, the source device 105 may continuously modify its settingsaccording to the current conditions being experienced by the primarysink device 110 and the secondary sink device 115.

By using the second sink-source coordination mechanism, the primary sinkdevice 110 and the secondary sink device 115 may be capable of providinginformation to the source device 105 so that the source device 105 maymodify the settings used to transmit subsequent packets so that both theprimary sink device 110 and the secondary sink device 115 have anincreased probability of receiving the packet. By performing the secondsink-source coordination mechanism, the mechanism may allow for linkstatistics to be provided by an inexplicit protocol (e.g., embedded intransmissions meant to carry other types of data) to the source device105. By providing the link statistic information, the source device 105may utilize more advanced power control schemes through incorporation ofvarious factors, may utilize beam forming to increase the likelihoodthat a packet is received by a particular sink device, may utilize MIMOto reduce the transmission and/or reception time, etc. Furthermore,since the second sink-source coordination mechanism uses packets thatare bound to respective destinations (e.g., rather than a dedicatedpacket), the second sink-source coordination mechanism may alsominimally increase air-time for transmissions with a short feedbacklatency.

Because the first sink-source coordination mechanism and the secondsink-source coordination mechanism are substantially similar in approachwhere link statistic information of the primary sink device 110 and thesecondary sink device 115 are provided to the source device 105, thesecond sink-source coordination mechanism may also be used and/ormodified in a manner substantially similar to the first sink-sourcecoordination mechanism. For example, the second sink-source coordinationmechanism may be used as a general, dynamic determination for thesettings used by the source device 105 that controls transmissionsettings by balancing various considerations. In another example, thesecond sink-source coordination mechanism may be used in combinationwith other mechanisms (e.g., the sink coordination mechanisms).

Source Smart-Listen Mechanism

The source smart-listen mechanism is configured such that the sourcedevice 105 performs operations to ascertain information of the sinkdevices to modify the transmission settings that increase a likelihoodthat the packet is received by each of the sink devices. As will bedescribed below, the source smart-listen mechanism utilizes adetermining operation on the S2B link 120 to determine link statisticsof the primary sink device 110 and a listening operation on the B2B link125 to determine link statistics of the secondary sink device 115. FIG.9 shows a source smart-listen scenario 900 and corresponding mechanismfor the sink devices 110, 115 to receive a packet according to variousexemplary embodiments described herein. FIG. 9 shows exemplarycircumstances for which the source smart-listen coordination mechanismmay be used. As illustrated, the source device 105, the primary sinkdevice 110, and the secondary sink device 115 of FIG. 1 are shown withvarious transmissions.

The source smart-listen scenario 900 shows a first state 905 that maytrigger use of the source smart-listen mechanism. As illustrated, thesource device 105 may establish the S2B link 120 with the primary sinkdevice 110. The source device 105 may transmit a packet to the primarysink device 110 in a transmission 910. The secondary sink device 115 mayuse the eavesdrop 130 (illustrated as an eavesdrop 915) to attempt toreceive the packet. Again, in this example, the primary sink device 110may receive the packet and the secondary sink device 115 may not receivethe packet. The secondary sink device 115 may utilize the B2B link 125to transmit a NACK in a transmission 925 to indicate the packet was notreceived. The primary sink device 110 may receive the transmission 925and generate a NACK to be transmitted to the source device 105 in atransmission 920 over the S2B link 120.

To address scenarios such as the source smart-listen scenario 900, thesource device 105 may be configured to utilize a listening operation 930to listen to the B2B link 125. The source device 105 may listen whilethe B2B link 125 is being used for transmissions, particularly while thesecondary sink device 115 is transmitting data to the primary sinkdevice 110. For example, the source device 105 may listen to the B2Blink 125 while the secondary sink device 115 sends the indication 925.By listening to the B2B link 125, the source device 105 may determinelink statistics of the secondary sink device 115. For example, the RSSIor channel estimates of the secondary sink device 115 relative to thesource device 105 may be determined. The source device 105 may alsodetermine further information of the secondary sink device 115. Forexample, the source device 105 may determine a transmit power (e.g., ifa transmit power for a private ACK is different from a resting transmitscheme), a frequency hopping sequence of the secondary sink device 115(e.g., if the secondary sink device 115 uses different transmit powersto the source device 105 and to primary sink device 110), differentfrequency hopping sequences (e.g., if the primary sink device 110 andthe secondary sink device 115 uses different subnets than that of thesource device 105 and the primary sink device 110), etc. The sourcedevice 105 may perform the listening operation 930 to determine the linkstatistics at various times. For example, the source device 105 mayperform the listening operation 930 continuously, at predetermined timeintervals that correspond to use of the B2B link 125, etc. In aparticular implementation, after the source device 105 transmits apacket, during a remaining portion of a transmission window, the sourcedevice 105 may perform the listening operation 930 when the primary sinkdevice 110 and the secondary sink device 115 are likely to use the B2Blink 125 to, for example, exchange an indication as to whether thepacket was received by the secondary sink device 115.

The source device 105 may also determine link statistics for the primarysink device 110 using the S2B link 120. For example, the link statistics(e.g., channel estimates, RSSI, etc.) of the primary sink device 110 maybe determined based on the transmission 920 received from the primarysink device 110.

When the link statistics for both the primary sink device 110 and thesecondary sink device 115 have been determined by the source device 105,the source device 105 may process the link statistic information todetermine the appropriate settings to be used in transmitting subsequentpackets. Therefore, when the link statistics of the secondary sinkdevice 115 indicate that the packet is incapable of being received (asis the case in the state 905), the source device 105 may, for example,increase a transmit power for subsequent packets, change beam formingsettings, change MIMO settings, etc.

The source smart-listen scenario 900 may then lead to the second state950. For example, the source device 105 may have modified its settingsbased on the link statistics determined while in the first state 905.The second state 950 may include substantially similar aspects as thefirst state 905. For example, the source device 105 may transmit apacket to the primary sink device 110 in a transmission 955. Thesecondary sink device 115 may use the eavesdrop 130 (illustrated as aneavesdrop 960) to receive the packet. Upon receiving the packet usingthe eavesdrop 130, the secondary sink device 115 may transmit an ACK ina transmission 970 using the B2B link 125. The primary sink device 110may receive the transmission 970 and generate an ACK to be transmittedin a transmission 965 that both the primary sink device 110 and thesecondary sink device 115 received the packet. In addition, the sourcedevice 105 may continue to perform a listening operation 975 on the B2Blink 125. Accordingly, the source device 105 may continue to determinelink statistics for the primary sink device 110 (e.g., via thetransmission 965) and the secondary sink device 115 (e.g., via thetransmission 870). In this manner, the source device 105 may dynamicallymodify its settings according to the current conditions beingexperienced by the primary sink device 110 and the secondary sink device115.

The following provides an example of the source-smart listen mechanismwhen the source device 105 includes two radio cores and the determinedstatistics are used to change the beam forming and/or MIMO settings. Theexample is further described with respect to the source smart-listenscenario 900 of FIG. 9. In this example, the source device 105 sends thetransmission 910 including the packet using initial settings for beamforming and/or MIMO using one or both radio cores of the source device.Again, the primary sink device 110 receives the transmission 910, butthe secondary sink device 115 does not receive the transmission 910 viathe eavesdropping operation 915. As described above, the exemplarymechanism may also be used when the secondary sink device 115successfully receives the transmission 910 via the eavesdroppingoperation 915. The secondary sink device sends the transmission 925including the NACK (or ACK if the packet was successfully received).

The source device 105 listens to the transmission 925 to determine thestatus of whether the secondary sink device 115 successfully receivedthe packet and/or to determine channel estimates for the channel betweenthe secondary sink device 115 and the source device 105. These channelestimates may be determined for both radio cores of the source device105. The primary sink device 110 sends the transmission 920 includingthe NACK (or ACK if packet was successfully received by both sinks) tothe source device 105. The source device 105 may also determine channelestimates for the channel between the primary sink device 110 and thesource device 105 based on the transmission 920. These channel estimatesmay also be determined for both radio cores of the source device 105.The source device 105 may continue to update the channel estimates infrequency hopping systems as the devices use different frequencies tocommunicate.

In one example, a channel coefficient matrix may be developed for themultiple radio cores and different connections (e.g., core 0 and core 1of the source device and source to primary sink device connection andsource to secondary sink connection). Those skilled in the art willunderstand the generation of channel coefficient matrices. The matrixmay be continuously updated (e.g., over various frequencies, includingusing interpolation and extrapolation). These link statistics may thenbe used for selecting beam forming settings and/or MIMO settings asdescribed above.

The above exemplary implementation for the source smart-listen mechanismis to address the source smart-listen scenario 900 where the secondarysink device 115 does not receive the packet using the eavesdrop 130 andthe source device 105 increasing the transmit power for subsequentpackets. However, the source smart-listen mechanism may also be used asa general, dynamic determination for the settings used by the sourcedevice 105 that optimizes the source device 105 by balancing variousconsiderations. For example, there may be a priority to have both theprimary sink device 110 and the secondary sink device 115 to receive thepacket. Thus, power consumption may become an ancillary considerationand the transmit power may be increased. In another example, when boththe primary sink device 110 and the secondary sink device 115 receivethe packet, different considerations may take priority such as powerconservation on the source device 105. Accordingly, the sourcesmart-listen mechanism may also be used to adjust the settings of thesource device 105 for subsequent packets by considering this factor. Forexample, the transmit power may be lowered if the current conditionsallow for this modified setting. For example, a historical view may showthat a previous number of packets was successfully received by both theprimary sink device 110 and the secondary sink device 115 to indicatethat the transmit power may be re-evaluated.

By using the source smart-listen mechanism, the source device 105 may becapable of determining link statistic information of the primary sinkdevice 110 and the secondary sink device 115 so that the source device105 may modify the settings used to transmit subsequent packets so thatboth the primary sink device 110 and the secondary sink device 115receive the packet with an increased probability. By performing thesource smart-listen mechanism, the primary sink device 110 and thesecondary sink device 115 may continue operating without modification orincreased operations (e.g., that result in increased power consumption).Furthermore, the source smart-listen mechanism may provide for nofurther air-time used in transmissions with a short feedback latency.

The various mechanisms of the exemplary embodiments may be used in anindividual manner but may also be used in combination. Select exemplarycombinations of the mechanisms are described above. However, thoseskilled in the art will appreciate that different combinations of themechanisms may be used to provide, for example, a fallback position, aredundancy operation, etc. that increases the probability that theprimary sink device 110 and the secondary sink device 115 receives thepacket successfully.

The exemplary embodiments provide a device, system, and method forproviding mechanisms that increase a probability that a plurality ofsink devices properly receive a packet transmitted by a source device.The exemplary embodiments may provide a plurality of sink coordinationmechanisms, a plurality of sink-source coordination mechanisms, and asource smart-listen mechanism. In a first sink coordination mechanism,the sink devices may be configured to dynamically determine arelationship to be used between one another and with the source deviceby selecting which of the sink devices is the primary while theremaining ones are secondary. In a second sink coordination mechanism,the sink devices may be configured to utilize a relay operation for apacket that is received by one of the sink devices to be relayed toanother one of the sink devices that did not receive the packet. In athird sink coordination mechanism, the primary sink device may utilizelink statistics of the secondary sink devices to reduce a transmit powerthat results in a transmit power of the source device to be increased.In a first sink-source coordination mechanism, the sink devices maygather link statistics of themselves and provide the link statistics tothe source device explicitly in a dedicated packet so that the sourcedevice may modify settings used in transmitting packets. In a secondsink-source coordination mechanism, the sink devices may gather linkstatistics of themselves and provide the link statistics to the sourcedevice inexplicitly in packets that are used for different purposes sothat the source device may modify settings used in transmitting packets.In the source smart-listen mechanism, the source device may determinelink statistics of the sink devices based on transmissions directly fromthe sink devices or transmissions between the sink devices so that thesource device may modify settings used in transmitting packets.

Those skilled in the art will understand that the above-describedexemplary embodiments may be implemented in any suitable software orhardware configuration or combination thereof. An exemplary hardwareplatform for implementing the exemplary embodiments may include, forexample, an Intel x86 based platform with compatible operating system, aWindows OS, a Mac platform and MAC OS, a mobile device having anoperating system such as iOS, Android, etc. In a further example, theexemplary embodiments of the above described method may be embodied as aprogram containing lines of code stored on a non-transitory computerreadable storage medium that, when compiled, may be executed on aprocessor or microprocessor.

It is well understood that the use of personally identifiableinformation should follow privacy policies and practices that aregenerally recognized as meeting or exceeding industry or governmentalrequirements for maintaining the privacy of users. In particular,personally identifiable information data should be managed and handledso as to minimize risks of unintentional or unauthorized access or use,and the nature of authorized use should be clearly indicated to users.

It will be apparent to those skilled in the art that variousmodifications may be made in the present disclosure, without departingfrom the spirit or scope of the disclosure. Thus, it is intended thatthe present disclosure cover the modifications and variations of thisdisclosure provided they come within the scope of the appended claimsand their equivalents.

1-20. (canceled)
 21. A method, comprising: at a first sink deviceconnected to a source device via a first communication link andconnected to a second sink device via a second communication link:determining a first link statistic associated with the firstcommunication link; receiving, from the second sink device, a secondlink statistic associated with the second sink device eavesdropping onthe first communication link; comparing the first link statistic withthe second link statistic; and performing a role switch based at leaston the comparison, wherein the role switch comprises disconnecting thefirst communication link and configuring the first sink device toeavesdrop on subsequent communications between the second sink deviceand the source device.
 22. The method of claim 21, wherein the roleswitch further comprises: sending an indication to the second sinkdevice that the second sink device should establish a thirdcommunication link with the source device.
 23. The method of claim 21,wherein comparing the first link statistic with the second linkstatistic indicates that the second sink device is receiving a strongersignal.
 24. The method of claim 21, wherein comparing the first linkstatistic with the second link statistic indicates that the second sinkdevice is receiving a weaker signal.
 25. The method of claim 21, whereinthe second link statistic is received periodically at a predeterminedinterval or when an event occurs.
 26. The method of claim 21, whereinthe first link statistic comprises a channel estimate or a receivedsignal strength indicator (RSSI).
 27. The method of claim 21, whereinthe first sink device comprises one of an audio bud, a wireless audiooutput device, a smartphone, a wireless earpiece, a wireless headset, awireless display device, a wearable, a Bluetooth-enabled hands-freeheadset, a wireless speaker, an intercom, a fitness tracking device, asensor, or an automobile sound system.
 28. A baseband processor of afirst sink device configured to perform operations comprising:connecting to a source device via a first communication link; connectingto a second sink device via a second communication link: determining afirst link statistic associated with the first communication link;receiving, from the second sink device, a second link statisticassociated with the second sink device eavesdropping on the firstcommunication link; comparing the first link statistic with the secondlink statistic; and performing a role switch based at least on thecomparison, wherein the role switch comprises disconnecting the firstcommunication link and configuring the first sink device to eavesdrop onsubsequent communications between the second sink device and the sourcedevice.
 29. The baseband processor of claim 28, wherein the role switchfurther comprises: sending an indication to the second sink device thatthe second sink device should establish a third communication link withthe source device.
 30. The baseband processor of claim 28, whereincomparing the first link statistic with the second link statisticindicates that the second sink device is receiving a stronger signal.31. The baseband processor of claim 28, wherein comparing the first linkstatistic with the second link statistic indicates that the second sinkdevice is receiving a weaker signal.
 32. The baseband processor of claim28, wherein the second link statistic is received periodically at apredetermined interval or when an event occurs.
 33. The basebandprocessor of claim 28, wherein the first link statistic comprises achannel estimate or a received signal strength indicator (RSSI).
 34. Thebaseband processor of claim 28, wherein the first sink device comprisesone of an audio bud, a wireless audio output device, a smartphone, awireless earpiece, a wireless headset, a wireless display device, awearable, a Bluetooth-enabled hands-free headset, a wireless speaker, anintercom, a fitness tracking device, a sensor, or an automobile soundsystem.
 35. A first sink device, comprising: a transceiver configured tocommunicate with a source device via a first communication link and asecond sink device via a second communication link; and a basebandprocessor configured to perform operations comprising: determining afirst link statistic associated with the first communication link;receiving, from the second sink device, a second link statisticassociated with the second sink device eavesdropping on the firstcommunication link; comparing the first link statistic with the secondlink statistic; and performing a role switch based at least on thecomparison, wherein the role switch comprises disconnecting the firstcommunication link and configuring the first sink device to eavesdrop onsubsequent communications between the second sink device and the sourcedevice.
 36. The first sink device of claim 35, wherein the role switchfurther comprises: sending an indication to the second sink device thatthe second sink device should establish a third communication link withthe source device.
 37. The first sink device of claim 35, whereincomparing the first link statistic with the second link statisticindicates that the second sink device is receiving a stronger signal.38. The first sink device of claim 35, wherein comparing the first linkstatistic with the second link statistic indicates that the second sinkdevice is receiving a weaker signal.
 39. The first sink device of claim35, wherein the second link statistic is received periodically at apredetermined interval or when an event occurs.
 40. The first sinkdevice of claim 35, wherein the first link statistic comprises a channelestimate or a received signal strength indicator (RSSI).